NAME

Log::Report::Dispatcher::Try - capture all reports as exceptions

INHERITANCE

 Log::Report::Dispatcher::Try
   is a Log::Report::Dispatcher

SYNOPSIS

 try { ... };       # mind the ';' !!
 if($@) {           # signals something went wrong

 if(try {...}) {    # block ended normally

 my $x = try { read_temperature() };
 my @x = try { read_lines_from_file() };

 try { ... }        # no comma!!
    mode => 'DEBUG', accept => 'ERROR-';

 try sub { ... },   # with comma
    mode => 'DEBUG', accept => 'ALL';

 try \&myhandler, accept => 'ERROR-';
 try { ... } hide => 'TRACE';

 print ref $@;      # Log::Report::Dispatcher::Try

 $@->reportFatal;   # re-dispatch result of try block
 $@->reportAll;     # ... also warnings etc
 if($@) {...}       # if errors
 if($@->failed) {   # same       # }
 if($@->success) {  # no errors  # }

 try { # something causes an error report, which is caught
       failure 'no network';
     };
 $@->reportFatal(to => 'syslog');  # overrule destination

 print $@->exceptions; # no re-cast, just print

DESCRIPTION

The try works like Perl's build-in eval(), but implements real exception handling which Perl core lacks.

The Log::Report::try() function creates this ::Try dispatcher object with name 'try'. After the try() is over, you can find the object in $@. The $@ as ::Try object behaves exactly as the $@ produced by eval, but has many added features.

The try() function catches fatal errors happening inside the BLOCK (CODE reference which is just following the function name) into the ::Try object $@. The errors are not automatically progressed to active dispatchers. However, non-fatal exceptions (like info or notice) are also collected (unless not accepted, see new(accept), but also immediately passed to the active dispatchers (unless the reason is hidden, see new(hide))

After the try() has run, you can introspect the collected exceptions. Typically, you use wasFatal() to get the exception which terminated the run of the BLOCK.

Extends "DESCRIPTION" in Log::Report::Dispatcher.

METHODS

Extends "METHODS" in Log::Report::Dispatcher.

Constructors

Extends "Constructors" in Log::Report::Dispatcher.

$obj->close()

Inherited, see "Constructors" in Log::Report::Dispatcher

Log::Report::Dispatcher::Try->new($type, $name, %options)
 -Option       --Defined in             --Default
  accept         Log::Report::Dispatcher  depend on mode
  charset        Log::Report::Dispatcher  <undef>
  died                                    undef
  exceptions                              []
  format_reason  Log::Report::Dispatcher  'LOWERCASE'
  hide                                    'NONE'
  locale         Log::Report::Dispatcher  <system locale>
  mode           Log::Report::Dispatcher  'NORMAL'
  on_die                                  'ERROR'
accept => REASONS
charset => CHARSET
died => STRING

The exit string ($@) of the eval'ed block.

exceptions => ARRAY

ARRAY of Log::Report::Exception objects.

format_reason => 'UPPERCASE'|'LOWERCASE'|'UCFIRST'|'IGNORE'|CODE
hide => REASONS|ARRAY|'ALL'|'NONE'

[1.09] see hide()

locale => LOCALE
mode => 'NORMAL'|'VERBOSE'|'ASSERT'|'DEBUG'|0..3
on_die => 'ERROR'|'PANIC'

When code which runs in this block exits with a die(), it will get translated into a Log::Report::Exception using Log::Report::Die::die_decode(). How serious are we about these errors?

Accessors

Extends "Accessors" in Log::Report::Dispatcher.

$obj->die2reason()

Returns the value of new(on_die).

$obj->died( [STRING] )

The message which was reported by eval, which is used internally to catch problems in the try block.

$obj->exceptions()

Returns all collected Log::Report::Exceptions. The last of them may be a fatal one. The other are non-fatal.

$obj->hide(@reasons)

[1.09] By default, the try will only catch messages which stop the execution of the block (errors etc, internally a 'die'). Other messages are passed to the parent dispatchers.

This option gives the opportunity to stop, for instance, trace messages. Those messages are still collected inside the try object (unless excluded by new(accept)), so may get passed-on later via reportAll() if you like.

Be warned: Using this method will reset the whole 'hide' configuration: it's a set not an add.

example: change the setting of the running block

  my $parent_try = dispatcher 'active-try';
  $parent_try->hide('ALL');
$obj->hides($reason)

Check whether the try stops message which were produced for $reason.

$obj->isDisabled()

Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->mode()

Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->name()

Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->needs( [$reason] )

Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->type()

Inherited, see "Accessors" in Log::Report::Dispatcher

Logging

Extends "Logging" in Log::Report::Dispatcher.

$obj->addSkipStack(@CODE)
Log::Report::Dispatcher::Try->addSkipStack(@CODE)

Inherited, see "Logging" in Log::Report::Dispatcher

$obj->collectLocation()
Log::Report::Dispatcher::Try->collectLocation()

Inherited, see "Logging" in Log::Report::Dispatcher

$obj->collectStack( [$maxdepth] )
Log::Report::Dispatcher::Try->collectStack( [$maxdepth] )

Inherited, see "Logging" in Log::Report::Dispatcher

$obj->log($opts, $reason, $message)

Other dispatchers translate the message here, and make it leave the program. However, messages in a "try" block are only captured in an intermediate layer: they may never be presented to an end-users. And for sure, we do not know the language yet.

The $message is either a STRING or a Log::Report::Message.

$obj->reportAll(%options)

Re-cast the messages in all collect exceptions into the defined dispatchers, which were disabled during the try block. The %options will end-up as HASH of %options to Log::Report::report(); see Log::Report::Exception::throw() which does the job.

$obj->reportFatal()

Re-cast only the fatal message to the defined dispatchers. If the block was left without problems, then nothing will be done. The %options will end-up as HASH of %options to Log::Report::report(); see Log::Report::Exception::throw() which does the job.

$obj->skipStack()

Inherited, see "Logging" in Log::Report::Dispatcher

$obj->stackTraceLine(%options)
Log::Report::Dispatcher::Try->stackTraceLine(%options)

Inherited, see "Logging" in Log::Report::Dispatcher

$obj->translate(HASH-$of-%options, $reason, $message)

Inherited, see "Logging" in Log::Report::Dispatcher

Status

$obj->failed()

Returns true if the block was left with an fatal message.

$obj->showStatus()

If this object is kept in $@, and someone uses this as string, we want to show the fatal error message.

The message is not very informative for the good cause: we do not want people to simply print the $@, but wish for a re-cast of the message using reportAll() or reportFatal().

$obj->success()

Returns true if the block exited normally.

$obj->wasFatal(%options)

Returns the Log::Report::Exception which caused the "try" block to die, otherwise an empty LIST (undef).

 -Option--Default
  class   undef
class => CLASS|REGEX

Only return the exception if it was fatal, and in the same time in the specified CLASS (as string) or matches the REGEX. See Log::Report::Message::inClass()

DETAILS

Extends "DETAILS" in Log::Report::Dispatcher.

OVERLOADING

overload: boolean

Returns true if the previous try block did produce a terminal error. This "try" object is assigned to $@, and the usual perl syntax is if($@) {...error-handler...}.

overload: stringify

When $@ is used the traditional way, it is checked to have a string content. In this case, stringify into the fatal error or nothing.

SEE ALSO

This module is part of Log-Report distribution version 1.31, built on January 15, 2021. Website: http://perl.overmeer.net/CPAN/

LICENSE

Copyrights 2007-2021 by [Mark Overmeer <markov@cpan.org>]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://dev.perl.org/licenses/